Well I think I found the main culprit, after going through and tweaking all my accels and retraction settings, at least in PrusaSlicer.
I had "Only retract when crossing perimeters" turned on, which caused a bunch of my oozing.

But getting my acceleration and travel moves better tuned also proved benificial.
I found I could bump up all the accelerations by quite a bit, as well as the travel move speed which improved stringing as well.

Still have slight gaps inbetween the gyroid layers, but that could be because it's only 5% infill.
Thanks for your input Phaedrux.

Well I think I found the main culprit, after going through and tweaking all my accels and retraction settings, at least in PrusaSlicer.
I had "Only retract when crossing perimeters" turned on, which caused a bunch of my oozing.

But getting my acceleration and travel moves better tuned also proved benificial.
I found I could bump up all the accelerations by quite a bit, as well as the travel move speed which improved stringing as well.

Still have slight gaps inbetween the gyroid layers, but that could be because it's only 5% infill.
Thanks for your input Phaedrux.

@Phaedrux said in Infill slight underextrusion:

Do you notice the same thing on other infill patterns that don't have unsupported overhangs? Like grid, or cubic?

I tried grid, and at first glance it is better, but where the extruder starts the grid pattern there is still underextrustion, but it is much harder to see. And hard to photograph:

But I think the issue is probably with my retraction settings. I did go through the 'wizard' in KISSlicer, but it still needs tweaking. Do you happen to have a link to a good guide for that? I never spotted the guide for the volumetric extrusion but it's much easier to follow than others I found.

@Phaedrux said in Infill slight underextrusion:

@jrjones88 said in Infill slight underextrusion:

I had found the max volumetric flowrate for my hot end to be ~7.5mm^3/sec

PrusaSlicer allows you to set a volumetric speed limit on the speeds tab. This would cap your movement speeds to automatically stay within the limit.

I had forgotten I had set that a while ago in Prusaslicer...

Printed it out again with the max speeds set to 45mm/sec, and I guess the volumetric speed limit was in play for the previous prints as I can't really see too much of a difference.

Thanks!
I had found the max volumetric flowrate for my hot end to be ~7.5mm^3/sec (long bowden) but hadn't calculated the max speeds for that before.

Would make my max speed 44.6 mm/s so I'll try dropping the speeds a bit.

I always thought I was printing slow because other Rostock users self reported speeds of up to 100mm/sec.

I can't seem to get the infill in my prints to come out nicely. They always are a bit underextruded.
I've calibrated the extruder, and the solid layers and perimeters print out as I expect.

Just on infill, and I've noticed it on support structures a bit too, it seems to be underextruding.
I've used PrusaSlicer, KISSlicer, Cura, and I seem to get the same results.
I thought that the issue was adaptive layer heights, but I still get it a little bit with that feature turned off.

Any tips/ideas of how to improve this?
I thought I had my speeds on the conservative side (45 mm/s perimeters, 60mm/s infill)
Some pictures:

Gcode of the print:Circle Test.gcode
Printer settings: config.g
Duet Firmware:
Board: Duet WiFi 1.0 or 1.01
Firmware: RepRapFirmware for Duet 2 WiFi/Ethernet 2.04RC1 (2019-07-14b1)
Duet WiFi Server Version: 1.23

My printer is a Rostock Max V2

@exerqtor
Where I have my printer connected to is similar, and I'm not getting any issues uploading, so I would say that -70dBm is good enough.

I have -71dBm connected through a Ubiquiti AP-AC-LR
Unifi reports a -65 dBm signal and a TX rate of 65 Mbps
I have speeds of around 200-250 kb/s as well, which I had before too located closer to an AP.

FYI my phone connected to the same AP has a self reported signal of -65dBM and a TX rate of 130 Mbps, while Unifi reports it has a -82 dBm signal and TX rate of 234 Mbps. My phone is about 4 meters further away from the AP.

@wyvern said in Yet another cast aluminum plate topic...:

Not to take over the thread, but has anyone used 3M 468MP to attach a mirror to an aluminum bed?

I hate hate hate hate hate clips or the likes, they get in the way and reduce build area.

I restrain my glass plate in 3 directions from the side. I still need to modify (improve) it since the heat cycling loosens the screws over time, but the aluminum is flat enough that after polishing it, if I lift only the glass, the aluminum sticks to it for a few seconds and is lifted up as well.
I usually have to slide the glass plate off the aluminum plate to separate them.
I was using the binder clips before but found that it warped the glass slightly because they clamped at the very edge of the glass.

Here is another place that sells off cuts of cast aluminum, out of California: http://www.sandsmachine.com/alumweb.htm

@arnix said in Suggestion for servo motor --> big delta robot:

Sorry for late reply.

To better understand my situation, am sending latest videos. One is with slower and second is on top speed.
Its without up/down movement, just positioning and extruder should position itself on X0 Y0 ( at higher speed it misses cca 10 cm ).

1.) https://ufile.io/u2cim ( just click, free slow download / open or save ).
2.) https://ufile.io/1t63o

@691175002 and @jrjones88
I think that the problem is in the gearing and lack of encoder. The material that am using at the moment aluminum but pipe wall is 2mm and pipe diameter is 2 centimeters so there should not be any problems, IMHO. As you guys point it out, 10:1 gearbox that am using could be the main problem because it has backlash of 3 degrees which is a lot, at no load. This is the stepper motor that am using :
https://www.omc-stepperonline.com/spur-gearbox/nema-23-stepper-motor-bipolar-l76mm-w-gear-raio-101-spur-gearbox-23hs30-2804s-sg10.html

High ratio belt reducer - DIY :

• i can do that, can you guys suggest some optimal ratio and motor ?
• what kind of setup would you suggest ( power supply, controller, etc. ) that can be controlled by duet ?

Yes your backlash is the issue right now. For the optimal ration and motor, that is a compromise between speed and holding power. Since you have a 1.89 Nm geared to 10:1 right now and it is too slow (you said cycle time is 1.5 seconds, desired is 1 second), your gearing needs to be a smaller ratio, say 8:1 or 5:1.

A belt reduction is a good way to reduce backlash, but depends on how much room you have. If you goto a 5:1 ratio, you might need a new motor as well, since your output torque is reduced by half on your current motor.

I don't know what your budget is (is this hobby or work/school?). If it isn't hobby I would look at Oriental Motors, they have good motors (all kinds) and drives (that accept pulsed input). But you are looking at around $500-1000 per motor/drive combination.
For example, this motor is has 0.05° backlash. https://catalog.orientalmotor.com/item/az-series-absolute-encoder-stepper-motors/az-series-85-mm-absolute-encoder-stepper-motors-dc/azm98ac-hp15

And once you reduce your backlash, I would still look at stiffening your frame (cross braces are easy to add in your case). Take a look here: https://youtu.be/p1Lrz0gPvOA
The frame is very beefy compared to the robot. This video also has some good views on the arms (very similar to the current Delta printers, but then again, delta pick and place robots have been around longer than delta 3d printers)

Could also use wood or melamine spacers.